One who is connected to a catheter, recites the bracha of asher yatzar to thank Hashem for allowing their catheter to function properly. If one (who is connected to a catheter) knows that their body has finished relieving itself for now, then they should make an Asher Yatzar. However, if there is a constant flow, one should recite the bracha once a day with the morning brachos. One who is on a dialysis machine R”l does not recite the bracha of asher yatzar.